The following commit has been merged into the objtool/urgent branch of tip:
Commit-ID: 1119d265bc20226c241e5540fc8a246d9e30b272 Gitweb: https://git.kernel.org/tip/1119d265bc20226c241e5540fc8a246d9e30b272 Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Tue, 28 Apr 2020 16:45:16 -05:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Thu, 07 May 2020 17:22:31 +02:00 objtool: Fix infinite loop in find_jump_table() Kristen found a hang in objtool when building with -ffunction-sections. It was caused by evergreen_pcie_gen2_enable.cold() being laid out immediately before evergreen_pcie_gen2_enable(). Since their "pfunc" is always the same, find_jump_table() got into an infinite loop because it didn't recognize the boundary between the two functions. Fix that with a new prev_insn_same_sym() helper, which doesn't cross subfunction boundaries. Reported-by: Kristen Carlson Accardi <kris...@linux.intel.com> Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Link: https://lkml.kernel.org/r/378b51c9d9c894dc3294bc460b4b0869e950b7c5.1588110291.git.jpoim...@redhat.com --- tools/objtool/check.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 4b170fd..0e8f9a3 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -72,6 +72,17 @@ static struct instruction *next_insn_same_func(struct objtool_file *file, return find_insn(file, func->cfunc->sec, func->cfunc->offset); } +static struct instruction *prev_insn_same_sym(struct objtool_file *file, + struct instruction *insn) +{ + struct instruction *prev = list_prev_entry(insn, list); + + if (&prev->list != &file->insn_list && prev->func == insn->func) + return prev; + + return NULL; +} + #define func_for_each_insn(file, func, insn) \ for (insn = find_insn(file, func->sec, func->offset); \ insn; \ @@ -1050,8 +1061,8 @@ static struct rela *find_jump_table(struct objtool_file *file, * it. */ for (; - &insn->list != &file->insn_list && insn->func && insn->func->pfunc == func; - insn = insn->first_jump_src ?: list_prev_entry(insn, list)) { + insn && insn->func && insn->func->pfunc == func; + insn = insn->first_jump_src ?: prev_insn_same_sym(file, insn)) { if (insn != orig_insn && insn->type == INSN_JUMP_DYNAMIC) break;
